TRANSACTIONS OF THE SECTIONS. 75 



Power to the Gisenian Academy of Catania, and are published, with Reports on them 

 by Profs, di Giacomo, Gemellaro and Maravigna, in the Transactions of the Academy, 

 vol. ix., and in the Journal of the Gitenian Literary Society for December 1834 ; in 

 the journal entitled ' Passe temps pour les Dames,' fifth year. No. 1 ; and in the ' Effe- 

 merido Scientifico e Letterario per la Sicilia,' No. Ixv. The principal results of these 

 observations, with a series of specimens of the young Argonauta, were submitted by 

 Madame Power to the Zoological Society of London in 1837, and gave rise to dis- 

 cussions which are detailed in the Proceedings of the Society for 1837, and are more 

 briefly summed up in the second volume of the Zoological Transactions, pp. 1 14, 115. 

 (See Athenaeum, No. 590.) But as the evidence adduced by Madame Power was 

 deemed by some naturalists to be inconclusive against the parasitism of the Cepha- 

 lopod inhabiting the Argonaut, Prof. Owen had suggested to Madame Power the 

 experiment of cutting oflF one of the membranous arms in a living Argonaut, and pre- 

 serving the mutilated Cephalopod alive as long as possible, to observe the elFect of 

 the operation on the growth or repair of the shell. 



Madame Power revisited Sicily in 1838, and transmitted to Prof. Owen, in 1840, 

 a letter descriptive of her ' Experiments and Observations upon the Argonauta Argo, 

 made during the months of October, November and December, 1839 ;' and Prof. Owen, 

 having recently received from Madame Power the specimens of the Argonaut experi- 

 mented on, which satisfactorily confirm the accuracy of the account of the experi- 

 ments and conclusions in that letter, proceeded to communicate the following trans- 

 lation of it to the Zoological Section of the Association : — 



" Honoured Friend. — In fulfilment of the gratifying charge you imposed upon 

 me, I present you with my slight work. It contains exactly the result of the obser- 

 vations which you, with so much judgement, proposed to me. I am aware that I 

 ought to have withdrawn from the task, not possessing sufficient scientific knowledge 

 for the undertaking, but the hope of kind indulgence encouraged me to proceed. 



"October 15th. — I placed my cages in the port of Messina, putting into them seve- 

 ral Argonauts, which had plenty of eggs suspended under the apex of the spire of the 

 shell, of which I measured the respective sizes. In order to ascertain what was 

 their favourite food, I gave them, in small pieces, Venuses, Crustacea, fish, flesh, and 

 a whole calamajo (Loligo sagittata, Lamarck), which is very common in the Messina 

 channel. They no sooner saw this last eatable, than they threw themselves upon it, 

 and it was curious to behold with what avidity they dragged it, now to the right, now 

 to the left, putting all their powers in action, and disputing among themselves for 

 victory and possession. 



"October 16th. — Having procured two more Argonautse, I cut from one of them the 

 right membranous arm, and from the other the left ; breaking oflF a piece from the 

 side of the shell of each corresponding with the cut arm. I then placed the Argonauts 

 in a cage*. The first died the day after, and the other five days after, and, in this, I 

 observed that the right portion of the shell exceeded, by about a line and a half, that 

 of the left, where the arm had been cut oft". [This is shown in specimen No. 1. — R. O.] 

 This convinced me that the animal, not having the left arm entire, could not in 

 consequence increase the shell on that side, while it proceeded in doing so on the 

 right side. I made several other trials, but without success, as all the animals died, 

 if not immediately, within a few hours after their being cut. 



" In order to succeed in my undertaking, I thought of breaking a piece oflF the ex- 

 tremity of the great whorl" (giro), "and performed this on six shells of the Argonaut, 

 to see whether the Cephalopod, after having repaired them, would proceed in aug- 

 menting them. In four, six and ten days the Cephalopods not only repaired them, 

 but proceeded to enlarge them, as the specimens Nos. 2 to 3 show. This is one of 

 the reasons which go to prove that the Cephalopod is the real fabricator of its own 

 shell, and confirms the statement made in my first memoirs. 



" October 28th. — I cut from four Cephalopods of the Argonaut about the half of 

 the membranous arms ; in two of them, cutting that on the right side, in the others, 

 that on the left, and I broke pieces, corresponding with the middle of the arm, out of 

 the shells. Two days afterwards I found them dead ; two only of them had repaired, 

 and but imperfectly, their shell ; one on the left side (No. 5) and the other on the 



* " It is necessary to perforin this operation in sea water of the same temperature as its 

 ordinary warmth, for if it be cold it kills the Argonauts." 



